<script>
import {defineComponent} from 'vue'

export default defineComponent({
  name: "a",
  data() {
    return {
      a: '123'
    }
  },
  watch: {
    a() {
      console.log('2')
    }
  }
})
</script>

<template>
  <div>123</div>
</template>

<style scoped>

</style>